If A Vigilante Contract killer that only takes contracts to kill the likes of Murderers, sexual and none-sexual Child Abuses, Rapists, Crime Lords, Drug Lords, Terrorists, War-Criminals, Government Level Traitors and corrupt senior people in the Army, Planetary Ocean and Space Navies, Air Force, Religious Groups and Police is hired to kill A Convicted, Sentenced to Life Means Life yet Escaped none-sexual Child Abuser that he knows is innocent but can't tell the authorities what he knows because it would mean revealing that he's the greatest contract killer his home subsector has ever known what would he do?

He/she would wake up one day, realise that by murdering dozens or hundreds of people he/she is a serial killer and therefore commit suicide because he/she is just as evil as the people he/she has killed.

These questions really are getting more niche!! Why does he have to reveal himself, why not release the info anonymously. Even then if the guy escaped he’s in trouble for shirking the due process of the law.

I would think that in a setting that allows licensed mercenaries and letters of marque, I would think it possible for a hit man who kills only criminals could be licensed as an "alive or dead" bounty hunter who doesn't bother trying to bring in criminals alive.